Conventionally, a laminated core used in a motor is manufactured by fabricating a laminated core body (core) having a plurality of magnet insertion holes in a circumferential direction thereof by laminating a plurality of core sheets, and after inserting permanent magnets respectively in the magnet insertion holes, placing the laminated core body between a resin injection die and a receiving die to compress the laminated core body in the laminating direction, and filling the magnet insertion holes with resin injected from resin reservoir pots provided to the resin injection die to perform resin sealing. (see Patent Document 1: Japanese Patent No. 4688505)
Moreover, in Patent Document 1, when the resin injection die comes into contact with the laminated core body, caulking protrusions (commonly called as caulking dowels) extending out of the laminated core body are housed in housing portions provided to the resin injection die so as to prevent resin leakage between the resin injection die and the laminated core body.
Furthermore, as illustrated in FIG. 8, in order to prevent resin from remaining on the surface of the laminated core body, a method has been proposed wherein an intermediate plate 66 (also called as a dummy plate, a cull plate or a tray) provided with gate holes 65 for connecting magnet insertion holes 62 with resin reservoir pots 63 is disposed between an upper die 60 serving as a resin injection die and a laminated core body 61 during resin sealing, and after the resin is injected from the gate holes 65 into the magnet insertion holes 62, the intermediate plate 66 is removed together with excess resin from the laminated core body 61. (see Patent Document 2: Japanese Patent No. 4991900)
On this intermediate plate 66, housing portions 68 are formed to house caulking protrusions 67 protruding from the surface of the laminated core body 61. Here, reference numeral 69 shows a lower die (a receiving die).